Method of making artificial limbs



Oct. 25, 1932. c. H. DAVIES METHOD OF MAKING ARTIFICIAL LIMBS Filed Aug. 15, 1931 FIG HGE ZYGFE I v 5 l 1 Z Z z 1 i F16? F16: I

II M

CHARLES H DA V/ES,

-45 tions from the metal shell Patented 1932 cm 1:. name, or PHILADELPHIA, :emmsrnvmm .mnrnon or name anrrarmn Lmns v Application filed August-'15, 1981. Serial No. 557374;.-

. It is the object and effect of my invention to form an'. artificial limb of which the prin- 7 cipalelement is a tube of thin metal, preferably aluminum, which is so worked during the rocess of forming th limbas to impart d described, both the metal shell and the skin to t e metal-the desired necessary for resistance stresses to which it will be sub] ected in actual egree of. rigidity use and which, otherwise,- would have the 10 effect of denting and otherwise distorting it.

' As hereinafter described, such working includes first compressing a primariliyi cylindrical tubeto form a coaxial zones of diflerent'diameters atdifierout regions of its length, in relative proportion to the diameters of the limb desired; then bending said its axis, 7

centric, according to the "shape of the limb desired. It maybe bowed outwardly or inwardly, or forwardly or rearwardly, with respect to the medial line of wearer to match the oppositel counterpart I naturallimb of the wearer.- aid eccentrically bent spindle is thereafter'expanded to the eccentric shape of the limb desired, while defining that shape by a mold surrounding said spindle; such expansion being conveniently effected by subjecting the bent spindle 83' to internal fluid pressure sufiicient to distort it into the irregular curvatures of the mold.

tube shown in Fig. III after it has been'mr- I have found a pressure of two thousand pounds per square inch purpose. 7

'Such a'sheet metal limb is-naturall resonant and use thereof is accompanied by a metallic sound caused by the vibration of themetal wall of the limb, unless means are provided to prevent the emission of sound 4o. vibrations from said .wall. Therefore, a further object and effect of my invention is to provide such a tubula-r'met'al limb with an artificial sln'n of material which is not only incapable of transmitting an sound vibraof 'the limb," but so constricts the latter as to suppress vibrations of the metal and render them inaudible. Such a skin is preferably formed of artificial cellulosic material expanded over and shrunk upon the metal o f the hmb'so as to continuthereof to the tubular spin e with spindle, transversely to torender said zones relatively ec'-- the Body of the,

satisfactory for that shown in ally constrict said metal shell. Such, an

artificial skin is preferably formed of material which is inherently colored to resemble natural skin. 7

Inthe form of my invention hereinafter 65 thereon are formed of seamless tubes in coherent relation.

My invention includes the various novel features of construction and arrangement and method of procedure hereinafter more definitely s ecified; the mold which defines the shape 0 the limb to which the metal tube is expandedis claimed in m copending application (215-31) Serial 0. 555,275 filed August 15, 1931, for Letters Patent of the United States.. I

In said drawing: Fig. I is a side elevation of a cyhndrical tube from which the artificial I limb is to be formed. Q

Fig. 'IIis' aside elevation of a tubular spindle includin coaxialzones "of different diameters at di erent regions of its length, conveniently formed from the primarily c lmdrical tube of Fig. Iby comprising said tube while spinning 1t. V

Fig. III is a front elevation of said spindle after it has been bent transversely to its axis to render said zonesrelatively eccentric, accordlng to the shape of the limb desired- '80 Fig. IV is a front elevation of the bent panded to the shape of the .limb desired. 1

Fig. V is aside elevation of said tube Fig.IV. x W "Fig. is a cross sectional view ofrsaid shellshown in Figs. IV'and V, taken on the lines .in those figures, showi a mold which surrounds said tubular she while it is bei1 1g expanded by internal fluid pressure.

1g. VII is a sectional view of said shell slmilar to Fig. VI but showing itprovided with a seamless artificial skin.

'I n said figures; the'metal tube 1 shown in ably, of the largest diameter desired for the l spindle 2, shown in Fig. IL Said spindle 2 is conveniently formed from said primarily cylindrical tube 1 by fitting within the latter a mandrel 3 which is of the shape desired for Fig. I, is primarily cylindrical and, prefer- .95

s t ere is no natural limb which is thus symmetrical, but every natural limb includes zones of different diameters throughout its length.which are in eccentric relation to each other. Therefore, I bend the spindle shell 2 in accordance with the eccentric shape desired for the artificial limb which is to be made therefrom. Such bending may be readily efiected without kinking the metal,

while said shell is packed with sand. Although Fig. III shows said spindle 2 distorted from its primarily coaxial form shown in Fig. II, by bending it in but one direction; it is to be understood that it may be bent transversely to its axis in several directions, for instance, it may be'bent laterally if the limb to be formedtherefrom is to be bowed or knock-kneed, and maybe bent either forwardly or rearwardly or spirally, in accordance with the oppositely counterpart natural limb which it is to match.

For instance, said benttubular spindle 2 shown in Fig.'III may thereafter be expended to the eccentric configuration of the artificial limb shell 7 shown in Figs. IV and V by stretching the metal of its wall outwardly throughout its length. Such expansion is conveniently effected by subjecting said spindle'2 to internal fluid pressure, preferably of water, and two thousand pounds per square inch, whiledefining the shape of said shell 7 by a mold surrounding said spindle. As indicated in Fig. VI, such a mold may be of split tubular form comprising oppositely counterpart sections 9 and 10 respectively mounted in the mold frame members 11 and 12 and having an internal configuration corresponding with that of' the metal shell 7,

shown in Figs. IV and V. To effect such ex.-:

pansion, thelopposite' ends of said spindle 2 are respectively connected in fluid tight relation with conduits 14 at theopposite ends of the mold and through which-the fluid under pressure is introduced to the interior of the spindle 2 with the effect of stretching and expanding the latter until it conforms to the irregular eccentric configuration of the interior of the mold which, as above indicated, corresponds with that of the metal shell 7 shown in Figs. IV and V, and which is known to the trade as a shin. I

However, it is it be understood that the process above described may be employed in the formation of an artificial thigh or forearm or upper arm. 5. 5

In any case I prefer to provide the metallic artificial limb member thus formed, and which is a seamless tube, with an artificial skin 15 which, as indicated in Fig. VII, is also a seamless tube and preferably formed by taking a primarily cylindrical tube of skin colored artificial cellulosic material, for instance pyroxylin, and whichis naturally hard, and softening it either by heating it in water or by application of a solvent such as an aqueous solution of cellulose acetate or an aqueous solution containing equal parts of acetone and ethyl alcohol. Then stretching it over the metallic limb shell, for instance the shell 7, and permitting said skin 15 to contract and set to hardened condition, thus constricting the metallic tube of the artificial limb and suppressing the natural tendency thereof to vibrate and emit sound vibrations.

Therefore,'I do not desire to limit myself to the precise details of construction and ar rangement and method of procedure herein set forth, as it is obvious that various modifications may be made therein without departing from the essential features of my invention, as defined in the appended claims.

I claim:

1. The method of forming an artificial limb, which includes forming a tubular metal spindle, open at each end, with coaxial zones of different diameters at different regions of its length, in relative proportion to the diameters of the limb desired; then bending said spindle, transversely to its axis, to render said zones relatively eccentric, according to the shape of the limb desired; and thereafter expanding said bent spindle to the shape of the limb desired.

'2. The method of forming an artificial limb, which includes forming a tubular metal spindle, open at each end, with coaxial zones of difierent diameters at difierent regions of its length, the diameters of the limb desired; then bending said spindle, transversely to its axis, to render said zones relativelyeccentric, according to the s ape of the limb desired, and thereafter ex nding said bent spindle to the shape of the limb desired, while defining that shape by a mold surrounding said spindle.

r 13. The method of forming an artificial limb, which includes spinning a seamless metal tube to form aspindle, open at each end, with'coaxial'zones of different diameters at different regions of its length, in relative proportion to the diameters of the limb desired;

. then bending said spindle, transversely to its axis, to render" said zones relatively eccentric, according to the shape of the limb desired; and thereafter expanding said bent spindle to the shape of the limb desired.

4. Themetho'd ,of forming an artificiallimb, which includes spinning a seamless metal tube to form a spindle, open at each end, with coaxial zones of different diameters at difi'erent regions of itslength, in relative proin relative proportion to V a then bending saidspindle,

' according to the shape of spindle to the shape portion to the diameters of the limb desired; then be'nding said spindle, transversely to its axis, to rendersaid zones relativelyeccentric, according to the shape of the limb desired; and thereafter expanding said bent spindle to the shape of the limb desired, while'defining that shape by a mold surrounding said spindle.

5. The method of forming an artificial limb, which includes compressing a seamless cylindrical metal tube to form a spindle, open to contract to solid form upon, and constrict, said metal tube. I

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania, this fifth day of August 1931.

. CHARLE H. DAVIES.

at each end, with coaxial zones of difierent diameters at different regions of its length, in relative proportion to the diameters of the limb desired; and thereafter expanding said spindle to the eccentric shape of the limb de-, sired, while defining that shape by a mold surrounding said spindle. V

6. The method of forming an artificial limb, which includes compressing and spinning a primarily cylindrical metal tube to form a spindle, open at each end, with coaxial zones of different diameters at different regions of its length, inrelative proportion to the diameters of the limb desired; transversely to its axis, to render said zones relatively eccentric, the limb desired; and thereafter eXpa-ndin said bent spindle to the eccentric shape 0 the limb desired, while defining that shape by a mold surrounding said spindle. r

7. The method of forming an artificial, limb, which includes forming atubular-met al spindle with coaxial zones of difierent diameters at different regions of its length, in relative proportion to the diameters of the limb desired; then bending said spindle, transversely to its axis, to render said zones relatively eccentric, according 'to the shape of the limb desired; then expanding said bent of the limb desired; and

- then covering said tube with a seamless skin limb, which includes of artificial cellulosic material, stretched upon and constricting said tube.

8. The method of forming an artificial spinning a primarily cylindrical metal tube to form aspindle with coaxial 'zones of different diameters at different regions of its length, in relative. pro-' portion to the diameters of the limb desired;

' then bending said spindle, transversely to its axis, to render said zones relatively eccentric,

then subjecting said bent spindle to internal fluid pressure until it is stretched and expanded to the shape of the limb; desired;

' while defining that shape by a mold surrounding said spindle; andthe expanded metal tube with a then providing tificial skin, under tension thereon, by softening a normally hard primarily cylindrical tube of artificial cellulosic material, stretching the same over the outersurface ofsaid metalftube and causing said cellulosic skin seamless ar-,

CERTIFICATE OF CORRECTION.

October 25, 1932.

Patent No. 1,884, 589.

CHARLES H. DAVIES.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 65, for serial number "555,275" read "557,275"; and line 75, for "comprising" read "compressing"; and that the said Letters Patent should be read with these cor= rections therein that the same may conform to the record of the case in the Patent Oitice. v

Signed and sealed this 6th day of December, A; D. 1932.

M. J. Moore;

(Seal) Acting Commissioner of Patents. 

